US20020141671A1 - Thin self-lubricating film/metallic bearing system and a method for implementing same - Google Patents

Abstract

A thin self-lubricating film bearing system including a mating structure having a mating surface, a substrate, wherein the substrate includes a substrate surface having a plurality of valleys, wherein the substrate is disposed so as to communicate the mating surface with the substrate surface and a lubricating material, wherein the lubricating material is disposed relative to the substrate so as to be communicated with the substrate surface and the mating surface. A method for implementing a self-lubricating film bearing system including obtaining a lubricating material and a substrate, wherein the substrate includes a substrate surface, processing the substrate surface so as to create a plurality of valleys within the substrate surface, cleaning the substrate surface so as to remove impurities from the substrate surface, applying the lubricating material to the substrate surface so as to dispose a thin film of the lubricating material on the substrate surface and associating the substrate with a mating structure having a mating surface, wherein the mating structure is disposed relative to the substrate such that the lubricating material is disposed between the substrate surface and the mating surface.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of U.S. provisional application No. 60/279,176, filed Mar. 27, 2001 the contents of which are incorporated by reference herein in their entirety.[0001]
BACKGROUND OF THE INVENTION
• This invention relates generally to a self-lubricating bearing system and a method for implementing a self-lubricating bearing system and more particularly to a thin self-lubricating film/metallic bearing system and a method for implementing same.[0002]
• Most existing bearing system designs utilize a thin dry film lubricant or grease to lubricate bearings used in applications that experience high loads such as static joints, small oscillatory motions or applications that experience high levels of vibration or micro-motion. However, one of the main problems observed with these designs is that the dry film lubricant or grease migrates out of the bearing resulting in fretting, galling, seizure or migration of the bearing in the bearing housing (rotational and/or axial movement). In an attempt to address this problem, bearing system designers have tried to apply self-lubricating PTFE or Teflon® fabrics and/or non-peelable PTFE or Teflon® liner systems. However, these systems do not have adequate load carrying capability and therefore cannot meet the stiffness requirements for these types of bearings.[0003]
• Therefore, there is a need for a self-lubricating bearing system and a method for implementing the self-lubricating bearing system, wherein the self-lubricating bearing system satisfies desired stiffness and load carrying requirements and wherein the method and system may be implemented in an inexpensive and reliable manner.[0004]
SUMMARY OF THE INVENTION
• A thin self-lubricating film bearing system comprising: a mating structure having a mating surface; a substrate, wherein the substrate includes a substrate surface having a plurality of valleys, wherein the substrate is disposed so as to communicate the mating surface with the substrate surface; and a lubricating material, wherein the lubricating material is disposed relative to the substrate so as to be communicated with the substrate surface and the mating surface.[0005]
• A method for implementing a self-lubricating film bearing system comprising: obtaining a lubricating material and a substrate, wherein the substrate includes a substrate surface; processing the substrate surface so as to create a plurality of valleys within the substrate surface; cleaning the substrate surface so as to remove impurities from the substrate surface; applying the lubricating material to the substrate surface so as to dispose a thin film of the lubricating material on the substrate surface; and associating the substrate with a mating structure having a mating surface, wherein the mating structure is disposed relative to the substrate such that the lubricating material is disposed between the substrate surface and the mating surface.[0006]
BRIEF DESCRIPTION OF THE DRAWINGS
• The above discussed and other features and advantages will be appreciated and understood by those skilled in the art from the following detailed description and drawings, wherein like elements are designated by like numerals in the several figures.[0007]
• Referring now to the drawings:[0008]
• FIG. 1 is a cross-sectional side view of a substrate communicated with a mating surface, showing self-lubricating reservoirs in accordance with an exemplary embodiment; and[0009]
• FIG. 2 is a flow diagram describing a method for implementing a self-lubricating bearing system in accordance with an exemplary embodiment.[0010]
DESCRIPTION OF A PREFERRED EMBODIMENT
• Referring to FIG. 1, a thin self-lubricating film/metallic bearing[0011]system1 is shown and described. In accordance with an exemplary embodiment a self-lubricating bearingsystem1 is illustrated and preferably includes asubstrate2, amating structure4 and alubricating material6.Substrate2 preferably includes asubstrate surface8 having a plurality ofplateaus12 and a plurality ofvalleys10, wherein eachvalley10 includes a valley depth d.Mating structure4 includes amating surface14, whereinmating surface14 is preferably a hard, smooth metallic surface. In accordance with an exemplary embodiment,mating structure4 is preferably a chrome plated metallic surface. However,mating structure4 may be constructed of a hardened corrosion resistant and/or stainless steel and/or metallic substrate that has been chrome plated, plasma sprayed and/or HVOF coated. In addition,mating structure4 may be constructed of any material or combination of materials suitable to the desired end purpose. In accordance with an exemplary embodiment,mating structure4 may be any hard, smooth metallic surface suitable to the desired end purpose, such as a shaft in a bushing product or against a ball in a spherical bearing product.
• In accordance with an exemplary embodiment,[0012]substrate2 is preferably constructed of a copper, nickel and/or tin material. However,substrate2 may be constructed from any material suitable to the desired end purpose.
• In accordance with an exemplary embodiment, lubricating[0013]material6 is preferably constructed from polymer (polyester) resin, lubricant particles such as Teflon® and/or graphite. In accordance with an exemplary embodiment, lubricating material6 (resin system) may be an epoxy, polyimide, urethane, phenolic or any other lubricatingmaterial6 suitable to the desired end purpose. Moreover, lubricatingmaterial6 preferably includes Teflon(and/or PTFE particles and/or fibers. These particles and/or fibers are preferably sold particles that are mixed with a liquid polymer resin that form a liquefied slurry mixture that turns into a homogenous solid material when the slurry mixture is cured (baked) during the fabrication process. Furthermore, lubricatingmaterial6 is preferably constructed from several types of resins so as to advantageously provide operational capability for thermal environments from about −200° F. to about +700° F.
• Lubricating[0014]material6 is preferably disposed relative tosubstrate surface8 so as to form athin film16 having a thickness a, coating the surface area ofsubstrate surface8. In addition,lubricant material6 is also preferably disposed relative tosubstrate surface8 so as to be disposed within plurality ofvalleys10. In accordance with an exemplary embodiment thickness a, ofthin film16 is preferably about 0.001 to about 0.005 inches thick.
• Referring to FIG. 2, a method for implementing a thin self-lubricating film/metallic bearing[0015]system100 is shown and described. In accordance with an exemplary embodiment, alubricating material6 and asubstrate2 having asubstrate surface8 is obtained as shown instep102. In addition amating structure4 having amating surface14 is also obtained.Substrate surface8 is then processed so as to create a plurality ofvalleys10 as shown instep104. In accordance with an exemplary embodiment,substrate surface8 is preferably processed by mechanically rougheningsubstrate surface8 via abrasive grit blast, controlled peening, a mechanical knurling process, drilling, machining and/or via any method and/or device suitable to the desired end purpose, such as chemical techniques (e.g., etching) or other mechanical techniques.
• In accordance with an exemplary embodiment,[0016]substrate2 is preferably constructed using a metal and/or a combination of metals that are corrosion resistant and that are selected for their resistance to galling and/or fretting while in contact withmating surface14. However,substrate2 may be constructed using any material suitable to the desired end purpose, such as beryllium copper, aluminum nickel bronze, copper nickel tin (per UNS C72900 and C96900), copper, brass, and spinoidal bronze, stainless steels, and plasma sprayed/high velocity oxy fuel (HVOF) materials.
• Once[0017]substrate surface8 is processed,substrate surface8 is then chemically cleaned so as to remove any impurities as shown instep106. In accordance with an exemplary embodiment,substrate surface8 is preferably cleaned using a chemical etchant. However,substrate surface8 may be cleaned using any alkaline cleaning solution and/or any solvent, method and/or device suitable to the desired end purpose. Lubricatingmaterial6 is then applied tosubstrate2 as shown instep108. In accordance with an exemplary embodiment,lubricating material8 is preferably applied so as to form athin film16 onsubstrate surface8 and so as to be contained within plurality ofvalleys10. Once lubricatingmaterial6 has been applied tosubstrate surface8,substrate2 is then disposed so as to be associated withmating structure4 as shown instep110. In accordance with an exemplary embodiment,mating structure4 is preferably disposed relative tosubstrate2 such thatlubricating material6 is disposed betweensubstrate surface8 andmating surface14.
• In accordance with an exemplary embodiment, lubricating[0018]material6 is preferably adhesively bonded tosubstrate2 and is preferably mechanically retained tosubstrate2 via the nature of the plurality ofvalleys10 formed insubstrate surface8 which traps or retainslubricating material6 withinvalleys10. When a high load is applied bymating surface14 ontosubstrate surface8, lubricating material is retained invalleys10 so that it cannot extrude out ofbearing system1. This advantageously prevents lubricatingmaterial6 from migrating out of the wear zone when thin self-lubricating film/metallic bearingsystem1 is exposed to high loads or vibration.
• In accordance with an exemplary embodiment, the combination of material used to construct[0019]substrate2, the processing ofsubstrate2 so as toroughen substrate surface8 and the use of a solid film of lubricatingmaterial6 advantageously combine to form a failsafe bearing system. When the bearing has worn through the thin self-lubricating film thickness a, there is residual lubricatingmaterial6 contained invalleys10. In addition, the unique properties of lubricatingmaterial6 advantageously allowslubricating material6 to work in combination with the bearing properties of the material used to constructsubstrate2.
• In accordance with an exemplary embodiment, as thin self-lubricating film/metallic bearing[0020]system1 operates, the thin film of lubricatingmaterial6 will wear until theplateaus12 ofsubstrate2 are in contact withmating surface4. Thelubricating material6 contained withinvalleys10 will then advantageously migrate so as to maintain a thin film of lubricatingmaterial6 betweenplateaus12 andmating surface4. This advantageously allows thin self-lubricating film/metallic bearingsystem1 to have a high load capability due to the reinforcement and support ofplateaus12 ofsubstrate2.
• In accordance with an exemplary embodiment, the shape of[0021]plateaus12 allowssubstrate2 to wear until an ideal area ratio is reached based on bearingsystem1 pressure, materials, lubricant, etc. This ideal area ratio allows thebearing system1 to reach an equilibrium point upon which the bearing will arrest further wear. The self-lubricating material is advantageously contained invalleys10 formed byprocessing substrate2. As this bearing experiences oscillations, vibrations, or micro-motion, lubricatingmaterial6 contained withinvalleys10 is continually dispersed to form a lubricant film transfer to themating surface14 andplateaus12 ofsubstrate2. This unique type of construction advantageously prevents the escape of particles of lubricatingmaterial6 from the wear zone as thevalleys10 act to catch, retain and re-apply lubricatingmaterial6 toplateaus12 ofsubstrate2 as thebearing system1 oscillates and/or rotates.
• In accordance with an exemplary embodiment,[0022]mating structure8 may be an integral component ofbearing system1, such as a spherical ball is a spherical bearing, and/ormating structure8 may be a separate component, such as a shaft which is inserted into a bushing and thus becomesmating structure8.
• While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.[0023]

Claims (17)

What is claimed is:

1. A thin self-lubricating film bearing system comprising:

a mating structure having a mating surface;

a substrate, wherein said substrate includes a substrate surface having a plurality of valleys, wherein said substrate is disposed so as to communicate said mating surface with said substrate surface; and

a lubricating material, wherein said lubricating material is disposed relative to said substrate so as to be communicated with said substrate surface and said mating surface.

2. The system according toclaim 1, wherein said mating structure is constructed of metal.

3. The system according toclaim 1, wherein said mating structure is constructed of metal having a plating/plasma spray/HVOF coating.

4. The system according toclaim 1, wherein said substrate is constructed of a metallic material having corrosion resistant properties.

5. The system according toclaim 1, wherein said lubricating material is constructed of polymer resin.

6. The system according toclaim 1, wherein said lubricating material is constructed of Teflon®.

7. The system according toclaim 1, wherein said lubricating material is constructed of PTFE material.

8. The system according toclaim 1, wherein said lubricating material is constructed of a graphite material.

9. The system according toclaim 1, wherein said lubricating material is capable of operating in thermal environments from about −200° F. to about +700° F.

10. The system according to clam1, wherein said lubricating material is disposed so as to form a material film on said substrate surface having a film thickness, a.

11. The system according toclaim 10, wherein said film thickness a is between about 0.001 inches thick and about 0.005 inches thick.

12. The system according toclaim 1, wherein said lubricating material is disposed relative to said substrate so as to be disposed within said plurality of valleys.

13. The system according toclaim 1, wherein said lubricating material is disposed so as to be between said substrate surface and said mating surface.

14. A method for implementing a self-lubricating film bearing system comprising:

obtaining a lubricating material and a substrate, wherein said substrate includes a substrate surface;

processing said substrate surface so as to create a plurality of valleys within said substrate surface;

cleaning said substrate surface so as to remove impurities from said substrate surface;

applying said lubricating material to said substrate surface so as to dispose a thin film of said lubricating material on said substrate surface; and

associating said substrate with a mating structure having a mating surface, wherein said mating structure is disposed relative to said substrate such that said lubricating material is disposed between said substrate surface and said mating surface.

15. The method according toclaim 14, wherein said processing includes roughening said substrate surface via grit blasting.

16. The method according toclaim 14, wherein said processing includes roughening said substrate surface via a knurling process.

17. The method according toclaim 14, wherein said processing includes roughening said substrate surface via chemical etching.

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